期刊
APPLIED SURFACE SCIENCE
卷 256, 期 5, 页码 1443-1451出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.apsusc.2009.08.105
关键词
Deuterium; Monte Carlo simulations; Potential energy surface; Physical adsorption; MgO
类别
资金
- Natural Science and Engineering Research Council of Canada
- Hashemite University, Jordan
In response to recent helium atom scattering (HAS) and neutron scattering results, Monte Carlo simulations and perturbation theory calculations have been performed for D-2 on MgO(0 0 1). Monte Carlo simulations predict that D-2 molecules form a series of interesting structures, p(2 x 2) -> p(4 x 2) -> p(6 x 2), with coverages Theta = 0.5, 0.75, 0.83 respectively, and followed by a formation of a top layer of p(6 x 2) unit cell symmetry. The three types of mono-layers are stable up to 13 K, whereas the top layer still exists up to 10 K. This is in partial agreement with the neutron scattering and HAS results that report c(2 x 2), c(4 x 2) and c(6 x 2); they agree in terms of coverage and stability, but disagree in terms of symmetry. A quantum mechanical examination of the D-2 molecules' rotational motion shows the molecular axes are azimuthally delocalized and hence the simulated structures are c-type rather than p-type. These calculations also indicate that ortho-D-2 and helicoptering para-D-2 prefer cationic sites, while cartwheeling para-D-2 prefers anionic sites. (C) 2009 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据